Refractory lining of furnaces having tubular walls



July 14, 194 2. A A. w. ABENNIS REFRACTORY LINING OF FURNACES HAVING TUBULAR WALLS Filed Sept. 3', 1940 C Figm Patented July 14, 1942 REFRACTORY LINING F FURNACESHAV- ING TUBULAR WALLS Alfred William Bennis, Little Hulton, Bolton, England Application September 3, 1940, Serial No. 355,261

In Great Britain July 10,1939

(CL 122-6A) Claims.

This invention relates to improvements in the refractory linings of furnaces having tubular walls and is particularly applicable to steam generator furnaces provided with tubular side walls or other parts through which the water and/or steam circulates and which are encased in refractory material to protect the tubes from the direct heat of the furnace.

In this type of steam generator furnace the temperatures maintained are so high that it becomes necessary to protect the tubes from the direct heat of the furnace and the protection usually takes the form of refractory brick or tile work, partly or wholly surrounding the tubes, so thatv heat is transmitted through this brickwork to the tubes. This causes evaporation of the water in the tubes whilst the tubes act as a cooling surface for the refractory brickwork and prevent undue deterioration of the latter Whilst permitting a high rate of heat transmission from the furnace to the tubes.

As the tubes expand and contract, it is necessary to bind or lock in place the bricks or tiles which comprise the refractory brickwork. Hitherto the bricks or tiles have been locked in place in such a manner that when repairs to the brickwork become necessary a considerable portion of the brickwork has to be cut away in order to repair the damaged part or else the bricks ortiles are held in position by bolts, studs or similar devices which, being exposed to the heat of the furnace quickly deteriorate and do not therefore afford a very" satisfactory method of securing the brickwork in position.

The object of the present invention is to provide a refractory lining which is composed of bricks or tiles and in which the disadvantages previously mentioned are obviated.

According to this invention the refractory lining is formed of bricks or tiles embracing the tubes and comprises front and rear walls in which the bricks forming the rear wall engage with and lock in position the bricks of the front wall in such a manner that the bricks in the front wall can be removed after their respective locking bricks in the rear wall have been removed.

This invention will now be more particularly described with reference to the accompanying drawing which illustrates by way of example a method of carrying out this invention and in which Fig. 1 is a front elevation of part of a tubular side wall encased in refractory bricks or tiles,

Fig. 2 is a sectional elevation taken on the line X--X of Fig. 1, and

Fig. 3 is a sectional plan taken on the line Y-Y of Fig. 1.

Fig. 4 is a front elevation of one of the bricks of the front wall,

Fig. 5 is a side elevation looking in the direction of the arrow a,

Fig. 6- is a side elevation looking in the direction of the arrow b, and

Fig. 7 is a plan of one of the bricks or tiles from which the front wall of the refractory lining is formed,

Fi 8- is a front elevation of one of the bricks of the rear wall,

Fig. 9 is a side elevation looking in the direction of the arrow 0,

Fig, 10 is a side elevation looking in the direction of the arrow (1, and

Fig. 11 is a plan of one of the bricks or tiles from which the rear wall of the refractory lining is formed.

Like letters indicate like drawing.

In carrying out this invention the refractory lining is built up of bricks or tiles and comprises parts throughout the bricks or tiles A forming a front wall on the side of the tubes B nearest to the furnace and bricks or tiles C forming a rear wall on the side of the tubes B remote from the furnace. The

. bricks or tiles comprising the front and rear wall are provided with recesses on their inner faces which embrace the tubes and the front or outer face of the front wall and the rear or outer face of the rear wall are disposed in planes substantially parallel to the plane in which the tubes are disposed.

The bricks or tiles A forming the front wall are of any convenient thickness and are provided in their rear face, approximately in the middle thereof, with a semi-circular recess D adapted to embrace one half of a tube. The rear face of the brick is not however parallel to the front face but is arranged so that it lies in a plane which is at an angle thereto as clearly shown in Figs. 3 and '7. In the drawing the plane of the rear face of the bricks A is shown as passing through the centre of one tube and as tangential with or approximately tangential with the adjacent tubes, but it will be understood that any other convenient angle between the planes of the front and rear faces of the bricks A may be adopted. The end faces of the brick or tile are disposed parallel with each other and approximately at right angles to the plane of the rear face as shown in Figs. 3 and 7 so that it will be seen that the end faces of the brick or tiles are of unequal length and lie in The steps formed in the rear face of the front wall will come between the tubes B and in order to lock the bricks forming the front wall in position the following arrangement is adopted. A recess E which is V shaped in plan and having one side longer than the other is provided in the longest end face of the brick close up to the inner or rear corner as shown in Fig. 7. The longest side E of this recess corresponds in plan with a line drawn from the rear corner of the brick towards the front face and at right angles thereto and the short side E with a line which is a continuation of the rear face of the next adjacent brick. It will be appreciated that the stepped formation of the rear face of the front wall is still maintained but that the faces of the steps, which are formed by the longest side E of the recess described, are at right angles to the front face of the wall.

The bricks C forming the rear wall preferably extend from the centre line of one tube to that of the next and have their front or inner faces stepped to correspond with the steps formed in the rear or inner face of the front wall so that they engage therewith as shown in Fig. 3, when laid in position. They are shaped at their inner corners to fit up to the tubes and their end faces are disposed in planes at right angles to the rear face of the bricks. It will therefore be readily understood that when the bricks C forming the rear wall are laid in position the step F (see Fig. 11) in the front faces of the latter will engage in the steps formed in the rear face of the front wall as shown in Fig. 3 and the bricks A in the latter will be locked in position as in order to remove one of these it must be withdrawn obliquely and this is prevented as the face E formed by the longest side of the recess E at the innermost corner of the brick is in engagement with the face F of the step F formed in the front face of the brick C in the rear Wall.

The bricks are secured in position with semiheat conducting cement and a similar plastic cement may surround the tubes between the latter and the bricks to allow for some expansion and contraction of the tubes.

It will be understood that the invention is not limited in its application to tubes disposed in the same plane but is applicable in covering curved tubes such as the furnace arch or other parts in or adjacent to the furnace, and that the angles and inclinations of the faces of the bricks may be varied to produce the same effect.

With the arrangement described the bricks forming the front wall are locked in position but can be removed after the removal of a single locking brick in the rear wall. If desired the bricks in the rear wall may be laid so that their horizontal joints lie midway between those in the front wall but in this case it would be necessary to remove two bricks in the rear wall to release one in the front wall.

What I claim as my invention is:

1. A refractory lining for the tubular walls of a steam generator comprised of front and rear walls built of refractory elements embracing the tubes in which each of the elements forming one wall is provided with end faces disposed in parallel vertical planes arranged at an angle to the outer face of the brick and an inner face disposed in a vertical plane at an angle to the outer face of the brick and is cut away at the innermost corner to form a recess which is V shaped in plan and has one side disposed in a plane at right angles to the outer face of the brick and is engaged by an extension formed on the inner face of an element disposed in the other wall, and moved into and out of locking position in a plane substantially parallel with its upper and lower faces.

2. A refractory lining for the tubular walls of a steam generator comprised of front and rear walls built of refractory elements embracing the tubes in which each of the elements forming one wall is provided with parallel end faces disposed at an angle to the outer face of the element and an inner face disposed at an angle to the outer face of the element and is cut away at the innermost corner to form a recess which is V shaped in plan and has one side disposed in the same plane as and forms a continuation of the inner face of the next adjacent element and the other side is disposed in a plane at right angles to the outer face of the element and is engaged by an extension formed on the inner face of an element disposed in the other wall, and moved into and out of locking position in a plane substantially parallel with its upper and lower faces.

3. A refractory lining for the tubular walls of a steam generator furnace comprising front and rear walls built of refractory elements embracing the tubes in which each of the elements forming one Wall has end faces disposed in parallel planes at an angle to the outer face of the element and an inner face disposed in a plane which passes approximately through the center of one tube and lies approximately tangential to the next adjacent tube and is cut away at the innermost corner to form a recess which is engaged by an extension on the inner face of an element in the rear wall which is moved into and out of locking position in a plane substantially parallel with its upper and lower faces.

4. A refractory lining for the tubular walls of a steam generator furnace comprising front and rear walls built of refractory elements embracing the tubes in which each of the elements forming one wall has end faces disposed in parallel planes which are at an angle to the outer face of the element and approximately at right angles to the inner face of the element with the inner face of the element disposed at an angle to the outer face and cut away at the innermost corner to form a recess which is engaged by an extension on the inner face of an element in the other wall which is moved into and out of locking position in a plane substantially parallel with its upper and lower faces.

5. A refractory lining for the tubular walls of a steam generator comprising double walls built of refractory elements embracing the tubes in which each of the elements forming one wall extends approximately an equal distance on either side of a tube and have end faces disposed in parallel planes at an angle to the outer face of the element and an inner face which is disposed in a plane at an angle to the outer face of the element and is cut away at its innermost corner to form a recess which is engaged by an extension on the inner face of an element disposed in the other wall and which extends approximately from the center of one tube to the center of the next, and is moved into and out of locking position in a plane substantially parallel with its upper and lower faces.

ALFRED WILLIAM BENNI 

